Preparation of Functionalized Carbon-Coated Cobalt Nanoparticles with Sulfonated Arene Derivatives,a Study on Surface Functionalization and Stability

The functionalization of magnetic nanoparticles has been an important field in the last decade due to the versatile applications in catalysis and biomedicine. Generally, a high degree of functionalities on the surface of the nanoparticles is desired. In this study, covalent functionalization of various aromatic sulfonic acids on carbon-coated cobalt nanoparticles are investigated on surface functionalization yield and stability. The nanoparticles are prepared via covalent linkage of an in situ generated diazonium on the graphene-like surface. Adsorption and wash experiments were performed to confirm a covalent bonding of the naphthalene derivatives on the nanoparticle surface. With an increased number of sulfonic acid groups on the aromatic compound a significantly lower loading is observed on the corresponding functionalized nanoparticles. This can be counteracted by a change of nitrite species. With this method, nanoparticles with a high number of sulfonic acid groups can be produced.     

Glass and bioglass nanopowders by flame synthesis

The preparation of amorphous nanopowders by flame synthesis opens access to common soda-lime, metal-doped glasses or bioglasses in the range of 20-80 nm and offers an alternative to conventional wet-phase preparation, solid state reactions or melting.     

Genomic Encryption of Digital Data Stored in Synthetic DNA

Today, we can read human genomes and store digital data robustly in synthetic DNA. Herein, we report a strategy to intertwine these two technologies to enable the secure storage of valuable information in synthetic DNA, protected with personalized keys. We show that genetic short tandem repeats (STRs) contain sufficient entropy to generate strong encryption keys, and that only one technology, DNA sequencing, is required to simultaneously read the key and the data. Using this approach, we experimentally generated 80 bit strong keys from human DNA, and used such a key to encrypt 17 kB of digital information stored in synthetic DNA. Finally, the decrypted information was recovered perfectly from a single massively parallel sequencing run.     

Robust Chemical Preservation of Digital Information on DNA in Silica with Error‐Correcting Codes

Information, such as text printed on paper or images projected onto microfilm, can survive for over 500 years. However, the storage of digital information for time frames exceeding 50 years is challenging. Here we show that digital information can be stored on DNA and recovered without errors for considerably longer time frames. To allow for the perfect recovery of the information, we encapsulate the DNA in an inorganic matrix, and employ error‐correcting codes to correct storage‐related errors. Specifically, we translated 83 kB of information to 4991 DNA segments, each 158 nucleotides long, which were encapsulated in silica. Accelerated aging experiments were performed to measure DNA decay kinetics, which show that data can be archived on DNA for millennia under a wide range of conditions. The original information could be recovered error free, even after treating the DNA in silica at 70 °C for one week. This is thermally equivalent to storing information on DNA in central Europe for 2000 years.     

The nested simple conformal loop ensembles in the Riemann sphere

Simple conformal loop ensembles (CLE) are random collections of simple non-intersecting loops that are of particular interest in the study of conformally invariant systems. Among other things related to these CLEs, we prove the invariance in distribution of their nested full-plane versions under the inversion \(z \mapsto 1/z\).     

Calibration-free concentration determination of charged colloidal nanoparticles and determination of effective charges by capillary isotachophoresis

Although colloidal nanoparticles show an electrophoretic heterogeneity under the conditions of capillary electrophoresis, which can be either due to the particle-size distribution and/or the particle shape distribution and/or the zeta-potential distribution, they can form correct isotachophoretic zones with sharp-moving boundaries. Therefore, the technique of isotachophoresis permits to generate plugs in which the co-ions and counter ions of the original colloidal solution are removed and replaced by the buffering counter ions of the leading electrolyte. It is shown that analytical isotachophoresis can be used to measure directly, without calibration, the molar (particle) concentration of dispersed ionic colloids provided that the transference number and the mean effective charge number of the particles (within the isotachophoretic zone) can be determined with adequate accuracy. The method can also be used to measure directly the effective charge number of biomacromolecules or colloidal particles, if solutions with known molar (particle) concentration can be prepared. The validity of the approach was confirmed for a model solution containing a known molar concentration of bovine serum albumin.